Unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
In a battery charging circuit of a device, when the device's system current load exceeds what a current-limited charger can provide, the voltage output of the charger drops. This condition is referred to as “voltage collapse.” Battery charging circuits typically employ voltage collapse protection (VCP) capability to prevent voltage collapse and potential brownouts of the device. VCP operation typically involves connecting the battery to supplement the system load.
When the excessive system load goes away, current from the charger may begin to flow into the battery. If the battery is fully charged or if battery charging is not supposed to happen (e.g., because the battery is too cold or too hot or that charging would otherwise violate industry safety standards), then it is important to cut off the current flow from the charger at the termination of VCP.